Pectin gel and preparation method thereof

Abstract

The invention provides pectin gel and a preparation method thereof. The pectin gel comprises pectin and fat-soluble substances, the pectin comprises pectin; the weight-average molecular weight range of the pectin is 5.0 * 10 < 4 >-6.0 * 10 < 5 > Da, and the polymer dispersion coefficient is 1-6; in the structural domain of the pectin, HG is more than 30 mol%, and RG-1 is less than or equal to 35 mol%; hG is homogalacturonidan, and RG-1 is rhamnouronidan I type. The pectin gel is high in emulsion stability before being formed, so that the formed pectin gel has relatively good texture stability, the oil separation amount of water is low, and the taste of the pectin gel is relatively good.

Description

Technical Field

[0001] The invention belongs to the technical field of food and medicine, and particularly relates to pectin gel and a preparation method thereof. Background Art

[0002] Pectin is an acidic heteropolysaccharide formed by connecting D-galacturonic acid through α-1.4-sugar. It is widely found in the cell walls of higher plants, accounting for about 30% to 35%. It is a natural, green and healthy natural polymer. Pectin has excellent properties in hemostasis, antibacterial, lipid-lowering and detoxification, making it widely used in many fields such as health products, food additives, cosmetics and medicine. Pectin can also regulate the osmotic pressure and pH value of cells. Adding a certain amount of water can form a chewing gel with a certain hardness and modulus.

[0003] In recent years, pectin has been widely used as a food additive in the fields of food, medicine and health products to prepare gels containing fat-soluble substances. In the relevant research process, it was found that when the oil loading (such as OMEGA-3, sourced from algae oil, fish oil, linseed oil, etc.) of pectin gel is ≥10%, the gel performance and emulsification performance of the system are poorly compatible, or the oil droplet size is too large, the particle size distribution of the fat-soluble component is lateralized, or the gel structure is loose, and the water-locking and oil-holding capacity is insufficient, which manifests as "oil separation and water release". Furthermore, the higher the oil loading, the worse the product appearance stability.

[0004] At present, there are some relevant studies on pectin gel containing fat-soluble substances, but not many. For example, CN111803439A improves water-oil separation and taste texture problems through the combination of stabilizers; but based on the need for oil retention and stability, the stabilizers introduced are mainly saturated / hydrogenated fatty acids, which have the risk of introducing trans fatty acids. Oral use by humans may affect digestion and metabolism. Another example is CN114009566B, in which the main vegetable gum gel matrix component, sugar, is replaced by sugar substitutes. The texture of vegetable gum soft candy is maintained by the combination and ratio of sugar substitutes, and the oil loading is ≥10%. There are certain limitations, and oil separation and water discharge are prone to occur, which affects the appearance and the experience of the eating process, affects the content stability of fat-soluble substances in pectin gel, and further affects the digestion and absorption of the human body. Especially for vegetable gum gels with an oil loading of ≥10%, the existence of the water-oil interface of the system requires a system premise of compatibility and stable emulsion droplets, and then the texture is presented to further achieve texture improvement, but this patent fails to cover this technical scope.

[0005] In view of this, how to further improve the stability of pectin gel emulsion containing fat-soluble substances, so as to improve the texture stability of pectin gel and reduce water and oil separation, is of great significance for further improving the performance of pectin gel products. Summary of the invention

[0006] In order to solve the problems and shortcomings in the prior art, the present invention provides a pectin gel and a preparation method thereof. The pectin gel has high emulsion stability before molding, so the molded pectin gel has good texture stability, low water and oil separation, and good pectin gel taste.

[0007] According to the first aspect of the present invention, a pectin gel is provided, comprising pectin and a fat-soluble substance; the pectin comprises pectin; the weight average molecular weight of the pectin ranges from 5.0*10^4 to 6.0*10^5 Da, and the polymer dispersion coefficient is 1 to 6; in the structural domain of the pectin, HG>30mol%, RG-1≤35mol%; HG is homogalacturonan polysaccharide, and RG-1 is rhamnosuronan polysaccharide type I.

[0008] When pectin is combined with fat-soluble substances, the fat-soluble substances can fill the gaps in the pectin gel network, interact with the pectin molecules, and enhance the stability of the gel. However, the mutual constraints that may exist between them may affect the texture stability and water and oil separation of the pectin gel, and also affect the taste of the pectin gel. In particular, in pectin gels containing high levels of fat-soluble substances, whether it is high-sugar or low-sugar pectin gel, it is easy to have water and oil separation, which affects the texture stability and taste of the pectin gel. Therefore, it is of great significance for the further development of pectin gel to further improve the texture stability of pectin gels containing high levels of fat-soluble substances, reduce their water and oil separation, and improve their taste.

[0009] Therefore, the present invention effectively improves the stability of the mixed liquid (emulsion) before molding by controlling the weight average molecular weight, polymer dispersion index (PDI) and HG, RG-1 of pectin, thereby improving the texture stability of the pectin gel after molding, and also effectively reduces the water and oil separation of the pectin gel, greatly improving the storage stability of the pectin gel, and improving the taste of the pectin gel.

[0010] Specifically, first, regarding the weight-average molecular weight of pectin, if it is too small, the interaction between chains is weak, and there is a lack of sufficient chain length to construct a stable three-dimensional gel network structure. Even if a gel is formed, its strength is very weak because the short molecular chain leads to fewer connection points between molecules, and the constructed gel network is not tight and firm enough, which ultimately leads to insufficient elasticity and poor texture stability of the gel formed by pectin. The insufficient tightness and firmness of the gel network will also lead to problems such as easy water outflow and oil separation. If it is too large, the pectin has poor solubility and is not easy to form a uniform and stable system with other materials, especially the emulsion system is more easily affected. If the conditions are not properly controlled, the gel may not be formed or an uneven gel may be formed. If a gel is formed, it will also lead to excessive strength and hard texture, affecting the taste. It also lacks elasticity and flexibility, and is easy to break when subjected to external forces, which will also affect the storage stability of the pectin gel.

[0011] Second, regarding the polymer dispersion index (PDI), a large PDI means that the molecular weight distribution of pectin is wide, including a variety of molecules with different molecular weights. During the gel formation process, molecules with different molecular weights have different gelation behaviors, which makes it difficult to accurately control the gel formation time, and the quality of the gel is unstable, and there may be local over-gelation or under-gelation, which in turn affects the texture stability and taste of the pectin gel, while increasing the oil separation from the water; and if the PDI is too small, because pectin gels are generally complex formula systems, and there will be certain interactions between the various ingredients, if the PDI is too small, it means that the properties of pectin are relatively fixed, and it may not be able to form a variety of synergistic effects with other ingredients, resulting in reduced texture stability of the overall performance of the pectin gel, and increased oil separation from the water.

[0012] Third, regarding HG and RG-1, pectin is a complex polysaccharide existing in plant cell walls, containing homogalacturonic acid (HG), rhamnogalacturonic acid I (RG-1) and other structural domains. HG is the main structural domain of the pectin molecule, which is a linear homopolymer of α-1,4-galacturonic acid, known as the "smooth region", reflecting the gel properties of the main body; RG-I has a highly branched feature, known as the "hairy region", and its side chain has a strong ability to bind water and stabilize the gel network structure. When the HG content is too small, the cross-linking points between pectin molecules are reduced, and it is difficult to form a stable three-dimensional network structure, resulting in reduced gel strength, poor structural stability, and more sensitive to changes in environmental factors such as temperature, pH value, and ionic strength. The stability of the water-oil emulsion formed is even worse, so the formed pectin gel not only has poor texture stability, but is also more prone to water and oil separation. The present invention controls the HG content to be greater than 30 mol%, effectively ensuring the high stability of the water-oil emulsion, so that the pectin gel oil after molding has a higher strength, further ensuring that it has good texture stability, and reducing the amount of oil separation from the water. RG-1 has abundant neutral sugar side chains, which can increase the flexibility and steric hindrance of the pectin molecules, so that the gel has better elasticity. When the RG-1 content is too large, the elasticity of the gel will be further enhanced, and excessive elasticity may occur, causing the gel to be easily deformed when subjected to external forces, and this rebound force may destroy the original structure inside the gel, making the texture of the gel loose and reducing its stability. And when multiple pectin gels with excessive elasticity are stacked or contacted with each other, they cannot maintain their respective shapes like gels with stable textures under the action of gravity or other external forces, but are easily squeezed and deformed by each other, or even fused together, affecting the stability of the entire system. Therefore, the present invention controls RG-1 to be less than or equal to 35 mol%, which is conducive to avoiding the excessive elasticity of pectin gel and affecting its overall texture stability, and reducing the amount of oil separation from the water.

[0013] It should be noted that, because pectin gel is a formula system, there are certain interactions among the pectin, fat-soluble substances and other materials therein, and the present invention controls the weight-average molecular weight of pectin, polymer dispersion index (PDI), HG, and RG-1 values, so that the interactions among the components in the pectin gel reach a relatively balanced and stable state, especially promoting the stable existence of fat-soluble substances in the mixed system, and further optimizing the stability of the mixed liquid (emulsion) and the texture stability of the pectin gel after molding, reducing the amount of water and oil separation of the pectin gel, and improving its storage stability and taste.

[0014] Preferably, the weight average molecular weight of pectin is in the range of 8.0*10^4~5.0*10^5Da, and the polymer dispersion coefficient is in the range of 1~4. Further adjustment of the weight average molecular weight of pectin and the polymer dispersion coefficient is more conducive to the overall stability of the mixed liquid, and thus is more conducive to obtaining pectin gel with higher texture stability, less oil separation from water, and better taste.

[0015] Preferably, the molecular weight of pectin is measured using a multi-angle laser light scattering instrument.

[0016] Preferably, in the structural domain of pectin, HG=40~90 mol%, RG-1=4~30 mol%. Furthermore, if HG is too large, due to the strong interaction between molecules, syneresis is likely to occur. This will cause the water in the gel to be squeezed out, making the volume of the gel smaller and the texture tighter, affecting the appearance and quality of the product. If RG-1 is too small, the elasticity and toughness of the gel will be significantly reduced, making the gel more fragile and easy to break. Therefore, further limiting HG and RG-1 within a specific range is not only more conducive to obtaining a stable water-oil emulsion system, but also more conducive to obtaining a pectin gel with better balance of texture stability, water and oil separation, taste and other multi-faceted properties.

[0017] Preferably, HG=GalA-Rha, RG-1=2Rha+Ara+Gal; GalA is the mol% of galacturonic acid, Rha is the mol% of rhamnose, Ara is the mol% of arabinose, and Gal is the mol% of galactose, wherein the mol% of HG and RG-1 are obtained as follows: a. Use ion chromatography to determine the content Wt of GalA galacturonic acid, Gal galactose, Rha rhamnose, Ara arabinose, Xyl xylose, Glc glucose, and Fru fructose in 100g of pectin; b. Calculate the corresponding molar number M and their sum M according to the specific molar mass of the substance. 总 , according to mol%=M / M 总*100% to obtain the corresponding molar percentage. Relevant studies have shown that the approximate values ​​of HG and RG-1 calculated by the above formula are closer to the actual values, so the HG and RG-1 values ​​calculated by the above formula are more accurate.

[0018] Preferably, the pectin gel also includes sugar alcohols, the pectin gel also includes sugar alcohols, the sugar alcohols include a first sugar alcohol and a second sugar alcohol; the first sugar alcohol includes xylitol; the second sugar alcohol includes at least one of maltitol and sorbitol; or, the sugar alcohols include a first sugar alcohol, a second sugar alcohol, and a third sugar alcohol; the third sugar alcohol includes erythritol. Sugar alcohols can adjust the water activity and solids of the system, creating more favorable conditions for pectin to form gel. Regarding the types of sugar alcohols, sugar alcohols are generally present in a higher content in pectin gels, so they also have a relatively important influence on the overall performance of pectin gels. The present invention selects a specific type of sugar alcohol to make it have a good interaction with pectin and fat-soluble substances, thereby further promoting the texture stability of pectin gels, reducing its water and oil separation, and improving the taste.

[0019] Preferably, the sugar alcohol includes a first sugar alcohol and a second sugar alcohol, and the mass ratio of the first sugar alcohol to the second sugar alcohol is 1-30: 0.09-65; or, the sugar alcohol includes a first sugar alcohol, a second sugar alcohol and a third sugar alcohol, and the mass ratio of the first sugar alcohol, the second sugar alcohol and the third sugar alcohol is 1-30: 0.09-65: 0.1-10. Further controlling the type and ratio of sugar alcohols, the interaction between sugar alcohols and substances such as pectin and fat-soluble substances is more balanced, and the performance of each substance will not be affected, so it is more conducive to maintaining the balance and stability of the water-oil emulsion, thereby optimizing the texture stability of the formed pectin gel, reducing the amount of water and oil, and improving the taste of the pectin gel.

[0020] Preferably, the mass ratio of pectin, sugar alcohol, and fat-soluble substances is 0.5-5:10-70:5-50. Further limiting the mass ratio of pectin, sugar alcohol, and fat-soluble substances within a certain range is more conducive to the interaction between the three substances, and is also more conducive to the interaction between the three substances and other substances in the pectin gel system, promoting the balance and stability of the water-oil emulsion, and further optimizing the texture stability of the formed pectin gel, reducing the amount of water and oil, and improving the taste of the pectin gel.

[0021] Preferably, the pectin gel further comprises an emulsifier, and the mass ratio of pectin, sugar alcohol, fat-soluble substance and emulsifier is 0.5-5:10-70:5-50:0.02-1. Emulsifier is a key factor in the stability of water-oil emulsion, so it is necessary to add emulsifier to stabilize the water-oil emulsion. Controlling the amount of emulsifier within a certain range is more conducive to the stability of water-oil emulsion, and further more conducive to obtaining pectin gel with high texture stability, low water oil separation and good taste.

[0022] Preferably, the mass proportion of pectin in the raw materials for preparing pectin gel is 1-4%.

[0023] Preferably, the degree of esterification of pectin is >50%.

[0024] Preferably, the fat-soluble substance includes a fat-soluble physiologically active substance, and the fat-soluble physiologically active substance includes at least one of DHA algae oil, oil-soluble vitamins, evening primrose oil, arachidonic acid, linseed oil, gamma-linolenic acid oil, caprylic decanoate (MCT), safflower seed oil, milk thistle seed oil, maple seed oil, walnut oil, fish oil, coenzyme Q10, rice bran fatty alcohol, pumpkin seed oil, borage oil, acetylsalicylic acid, fat-soluble statins, antibiotics, naproxen, and antihistamines.

[0025] Preferably, the pectin gel further comprises an acidity regulator, and the mass ratio of pectin to the acidity regulator is 0.5-5:0.5-7.5.

[0026] Preferably, the emulsifier includes at least one of modified starch, phospholipids, gum, acetylated pectin, cholesterol, lanolin, saponin, polysaccharides, and proteins.

[0027] Preferably, the modified starch includes esterified starch; the phospholipids include at least one of soybean lecithin, modified lecithin, and enzymatic lecithin; and the gum includes gum arabic.

[0028] Preferably, the acidity regulator includes at least one of citric acid, sodium citrate, potassium citrate, malic acid and lactic acid.

[0029] Preferably, the pectin gel further comprises metal ions, and the metal ions include calcium ions. Preferably, the calcium ions are provided by calcium salts, and the calcium salts include at least one of calcium lactate, calcium citrate, tricalcium phosphate, calcium hydrogen phosphate, milk mineral salt, calcium gluconate, and calcium chloride.

[0030] According to a second aspect of the present invention, there is provided a method for preparing the above-mentioned pectin gel, comprising the following steps: preparing an aqueous phase: uniformly mixing pectin, part of the sugar alcohol and an acidity regulator to obtain a gel premix; uniformly mixing water, the remaining sugar alcohol and deformed starch, adding the gel premix thereto, and heating until completely dissolved to obtain an aqueous phase; preparing an oil phase: heating and mixing a fat-soluble substance until the liquid is uniform to obtain an oil phase; emulsifying: adding the oil phase to the aqueous phase and mixing uniformly, and performing high-speed shear emulsification at 70-95° C. to obtain an emulsion; blending: mixing an acidity regulator and water, mixing at 70-80° C. until completely dissolved, and adding the mixture to the emulsion and mixing for 5-10 minutes to obtain a liquid; and molding: pouring the liquid onto a blister, sealing it, and standing it for 40-60 hours to stabilize the molding.

[0031] Preferably, in the preparation process of the above-mentioned pectin gel, glycerol is added during the preparation of the aqueous phase, and the mass ratio of pectin to glycerol is 0.5-5:0.1-8. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 It is a schematic diagram of the centrifugal stability test of the mixed liquid (water-oil emulsion) in Examples 1 to 5 of the present invention and Comparative Examples 1 to 2.

[0033] Figure 2 Schematic diagram of the thermal stability test of the mixed liquid (water-oil emulsion) in Examples 1 to 5 of the present invention and Comparative Example 1. DETAILED DESCRIPTION

[0034] In order to enable those skilled in the art to better understand the solutions of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only embodiments of a part of the present invention, rather than all embodiments.

[0035] In the present invention, the pectin used in the examples and comparative examples is selected from standard commercial materials, and the material standards match the requirements of GB 25533. The following Table 1 shows the parameter information of each pectin on Mw, PDI, HG, and RG-1: Table 1 Summary of parameter information of each pectin regarding Mw, PDI, HG, and RG-1

[0036] Examples and Comparative Examples 1. Taking the Mw and / or PDI of pectin as variables, the effects of Mw and / or PDI on the water-oil emulsion and the formed pectin were investigated. Effect of gel.

[0037] A total of 6 embodiments and 3 comparative examples are provided above, and the formulations of the embodiments and comparative examples are shown in Table 2.

[0038] Table 2 Formulas of Examples 1 to 6 and Comparative Examples 1 to 3

[0039] 2. The effects of the types and ratios of sugar alcohols in pectin on water-oil emulsions and formed pectin gels.

[0040] A total of 15 embodiments are provided above, and the formula of each embodiment is shown in Table 3-1, Table 3-2, and Table 3-3.

[0041] Table 3-1 Formulas of Examples 7 to 12

[0042] Table 3-2 Formulas of Examples 13 to 18

[0043] Table 3-3 Formulations of Examples 19 to 21

[0044] 3. Taking pectin HG and / or RG-1 as variables, the effects of HG and / or RG-1 on water-oil emulsions and formed pectin were investigated. The effect of gel.

[0045] There are 3 embodiments and 1 comparative example in total, and the formulations of the embodiments and comparative examples are shown in Table 4.

[0046] Table 4 Formulas of Examples 22 to 24 and Comparative Example 4

[0047] Test Case 1. Experimental Construction Method (1) Preparation of pectin gel: Pectin gel was prepared using the formulas in all the above examples and comparative examples. The specific preparation steps are as follows: Preparation of aqueous phase: evenly mix pectin, part of sugar alcohol, and part of acidity regulator (sodium citrate, citric acid) to obtain a gel premix; evenly mix water, remaining sugar alcohol (if any, "if any" means that the sugar alcohol can also be directly added when preparing the gel premix), deformed starch, and glycerol, add the gel premix thereto, and heat until completely dissolved to obtain an aqueous phase; Preparation of oil phase: Heat the fat-soluble substance (DHA algae oil) to 90°C (if there are multiple fat-soluble substances, heat until they are evenly mixed and then keep warm), and keep warm to obtain the oil phase; Emulsification: Add the oil phase to the water phase and mix evenly, and perform high-speed shear emulsification at 90°C to obtain an emulsion; Preparation: Mix the remaining acidity regulator (citric acid) and water, mix at 70-80°C until completely dissolved, add to the emulsion and mix for 5-10 minutes to obtain a feed liquid; Molding: Pour the liquid material onto the blister, seal it, and let it stand for 48 hours to stabilize the shape.

[0048] (2) Performance testing ① Emulsion stability determination a. Centrifugal stability Take 10 g of the unformed pectin gel (liquid) after preparation into a centrifuge tube, balance it in a 75°C water bath for 30 min, centrifuge it at 3000 rpm for 10 min, and observe and record the stratification of the emulsion gel.

[0049] b. Thermal stability Take 10 g of the unformed pectin gel (liquid) after preparation into a centrifuge tube, place it in a 90°C water bath for 1 hour, take it out and centrifuge it at 3000 rpm for 10 minutes, observe and record the stratification of the emulsion gel.

[0050] c. Freeze-thaw stability Take 10g of the unformed pectin gel (liquid) after preparation into a centrifuge tube, seal it with an aluminum bag, and store it in a -20℃ refrigerator for 24 hours. Take it out and thaw it at room temperature for 24 hours, then centrifuge it at 3000rpm for 10 minutes, and observe and record the stratification of the emulsion gel.

[0051] ②Water discharge test Place 10 g of the stably formed pectin gel in a standard open container, put it into a constant temperature drying oven at 25±2℃ and 20~30%RH, dry it for 24h and 48h, and the drying loss / %= (M1-M2) / M1, and the drying balance=|(M1-M3) / M1-drying loss|. Repeat 3 times and take the average value; where M1 represents the weight before drying, M2 represents the weight after drying for 24h, and M3 represents the weight after drying for 48h.

[0052] ③Texture test SMS TA XT plus texture analyzer was used in TPA test mode with pre-test speed: 1 mm / s, test speed: 3 mm / s, post-test speed: 3 mm / s, trigger force: 5 g, target mode: deformation 50%. The pectin gel specifications and shapes were controlled to be consistent, round cake shape, 1.5 g / particle, and each group of samples was tested in parallel 6 times.

[0053] ④Disintegration time limit According to USP <2040> (medium water) for testing.

[0054] (3) Evaluation criteria The relevant properties of the emulsions (liquids) and the formed pectin gels in the examples and comparative examples were evaluated according to the evaluation criteria in Table 5 below.

[0055] Table 5 Evaluation criteria

[0056] 2. Experimental results The relevant performance evaluation results of the emulsions (liquids) in the examples and comparative examples and the molded pectin gels are shown in Tables 6-1 and 6-2.

[0057] Table 6-1 Performance evaluation results of Examples 1 to 21

[0058] Table 6-2 Performance evaluation results of Examples 22 to 24 and Comparative Examples 1 to 4

[0059] It can be seen from Tables 6-1 and 6-2 that the present invention effectively improves the stability of the mixed liquid (emulsion) before molding by controlling the weight average molecular weight of pectin, the polymer dispersion index (PDI) and limiting the type of sugar alcohol, thereby improving the texture stability of the pectin gel after molding, and effectively reducing the water and oil separation of the pectin gel, greatly improving the storage stability of the pectin gel, and improving the taste of the pectin gel. Please refer to the performance data in Examples 1 to 24 for details.

[0060] The weight average molecular weight Mw of pectin in Comparative Examples 1 and 2 is too low and too high, respectively, which is not conducive to the formation of a stable emulsion in the mixed liquid (emulsion), nor is it conducive to the stability of the texture of the pectin gel after molding, and even affects the molding of the pectin gel. As a result, the emulsion or oil-water stratification phenomenon after centrifugation in Comparative Examples 1 and 2 is serious. Figure 1 In the centrifuge tube pictures of Comparative Examples 1 and 2, the emulsion or oil-water after centrifugation has certain stratification or severe stratification. Figure 1 It can be seen that the weight average molecular weight Mw of Examples 1 to 5 is within a suitable range, so that their emulsions still have good stability after centrifugation and no obvious stratification. However, because Comparative Examples 1 and 2 cannot form a relatively stable emulsion, they cannot be formed into pectin gel or the texture stability of the formed pectin gel decreases, the amount of oil separation in the water is high, the comprehensive evaluation score is low, and the pectin gel is unqualified. And further refer to Figure 2 It can also be seen that compared with Examples 1 to 5, the thermal stability of the emulsion in Comparative Example 1 is worse, which also shows that the overall stability of the emulsion in Comparative Example 1 is poor, which is not conducive to the preparation of pectin gel with high texture stability and low water oil separation.

[0061] In Comparative Example 3, the polymer dispersion coefficient of pectin is too high, the molecular weight distribution of pectin is too wide, the emulsion stability decreases, the quality of the gel is also unstable, and the phenomenon of local excessive gelation or insufficient gelation is prone to occur, which in turn affects the texture stability of the pectin gel, making the comprehensive evaluation score of the final pectin gel also low, and it is also easy to produce water and oil, and the pectin gel is also unqualified. In Comparative Example 4, the pectin HG is relatively small, and the RG-1 is also relatively small, which leads to the decrease in emulsion stability in Comparative Example 4, and the texture stability of the pectin gel after molding is relatively poor, and the amount of water and oil is also relatively high, the comprehensive evaluation score is also low, and the pectin gel is unqualified.

[0062] Further comparing Examples 1 to 5 and Example 6, the weight average molecular weight Mw of pectin in Examples 1 to 5 is in a further preferred range of 8.0*10^4~5.0*10^5Da, while the weight average molecular weight Mw of pectin in Example 6 is not within this range, resulting in a lower comprehensive evaluation score of the pectin gel in Example 6, which indicates that further controlling the weight average molecular weight of pectin is more conducive to obtaining pectin gel with higher texture stability, less oil separation from water, and better taste. Similarly, the polymer dispersion index PDI of pectin is similar, and no examples are given here.

[0063] By observing Examples 7 to 21, it can be seen that in the process of preparing pectin gel, when the types of sugar alcohols include xylitol and maltitol (or sorbitol) and the ratio of each sugar alcohol is within a certain range, the prepared emulsion is relatively stable, the texture stability of the formed pectin gel is also high, the water retention and moisture resistance are good, the comprehensive evaluation score is high, and the pectin gel is qualified. It can be further found that when the types of sugar alcohols include three, the comprehensive evaluation score is higher, which shows that the three types of sugar alcohols and within a certain ratio range are more conducive to obtaining pectin gel with high texture stability, low water and oil separation, and good taste.

[0064] The above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit the protection scope of the present invention. Although the present invention is described in detail with reference to the above embodiments, ordinary technicians in the relevant field should understand that the technical solutions of the present invention can be modified or equivalently replaced, but these modifications or replacements are all within the protection scope of the present invention.

Claims

1. A pectin gel, characterized in that: Including pectin, fat-soluble substances; The pectin includes pectin; the weight average molecular weight of the pectin ranges from 5.0*10^4 to 6.0*10^5 Da, and the polymer dispersion coefficient ranges from 1 to 6; In the structural domain of the pectin, HG>30mol%, RG-1≤35mol%; HG is homogalacturonan, and RG-1 is rhamnosuronan type I.

2. The pectin gel according to claim 1, characterized in that: The weight average molecular weight of the pectin is in the range of 8.0*10^4~5.0*10^5Da, and the polymer dispersion coefficient is in the range of 1~4.

3. The pectin gel according to claim 1, characterized in that: In the structural domain of the pectin, HG=40~90 mol%, RG-1=4~30 mol%.

4. The pectin gel according to claim 1, characterized in that: The pectin gel further comprises sugar alcohols, wherein the sugar alcohols comprise a first sugar alcohol and a second sugar alcohol; the first sugar alcohol comprises xylitol; the second sugar alcohol comprises at least one of maltitol and sorbitol; Or, the sugar alcohol includes the first sugar alcohol, the second sugar alcohol, and a third sugar alcohol; and the third sugar alcohol includes erythritol.

5. The pectin gel according to claim 4, characterized in that: The sugar alcohol includes the first sugar alcohol and the second sugar alcohol, and the mass ratio of the first sugar alcohol to the second sugar alcohol is 1-30:0.09-65; Or, the sugar alcohol includes the first sugar alcohol, the second sugar alcohol and the third sugar alcohol, and the mass ratio of the first sugar alcohol, the second sugar alcohol and the third sugar alcohol is 1-30:0.09-65:0.1-10.

6. The pectin gel according to claim 4, characterized in that: Calculated by mass ratio, the mass ratio of the pectin, the sugar alcohol, and the fat-soluble substance is 0.5~5:10~70:5~50.

7. The pectin gel according to claim 6, characterized in that: It also includes an emulsifier. Calculated by mass ratio, the mass ratio of the pectin, the sugar alcohol, the fat-soluble substance, and the emulsifier is 0.5~5:10~70:5~50:0.02~1.

8. The pectin gel according to claim 1, characterized in that: The mass proportion of the pectin in the raw materials used to prepare the pectin gel is 1-4%.

9. The pectin gel according to claim 7, characterized in that: It also includes an acidity regulator, and the mass ratio of the pectin to the acidity regulator is 0.5-5:0.5-7.

5.

10. A method for preparing pectin gel according to any one of claims 1 to 9, characterized in that: The steps include: Preparation of aqueous phase: mixing the pectin, part of the sugar alcohol, and part of the acidity regulator evenly to obtain a gel premix; mixing water, the remaining sugar alcohol, and deformed starch evenly, adding the gel premix thereto, and heating until completely dissolved to obtain the aqueous phase; Preparation of oil phase: heating and mixing the fat-soluble substances until the liquid is uniform to obtain an oil phase; Emulsification: adding the oil phase to the water phase and mixing evenly, and performing high-speed shear emulsification at 70-95° C. to obtain an emulsion; Preparation: Mix the remaining acidity regulator and water at 70-80°C until completely dissolved, add into the emulsion and mix for 5-10 minutes to obtain a feed liquid; Molding: Pour the liquid material onto the blister, seal it, and let it stand for 40 to 60 hours to stabilize the molding.

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